Liquid sterilizing device



June 7, 1938. E. A. JOHNSTON f LIQUID STERIILIZINVG DEVICE original Filed July 16, 19:55

2 Sheets-Sheet l June 7', l'938. E. A. JOHNSTON l LIQUID STERILIZING DEVICE 2 s'nets-sheet 2.

Original Filed July 16,. 1935 V Patented June 7, 1938 UNITED STATES PATENT Lorrlcie.

LIQUID STERILIZING DEVICE Edward A. Johnston, Chicago, Ill., asslgnor to International Harvester Company, a corporation lof'New Jersey Application July 16, 1935, serial'No. 31,723

I Renewed November 27, 1937 'i claims. -(c1. sia-zw- Figure 1 is a side elevation of a complete 'mathat the milk be formed as a very thin uniform '-lm, preferably of a thickness less than onetenth of a millimeter. In order to handle a sufficient volume of milk to eil'ect treatment at adesired rate, it is also necessary to provide a large surface area on which the milk film is formed. Another important requirement is to provide an apparatus in which an atmosphere may be maintained which is transparent to the radiations which must reach the milk to effect the desired result. 'I'he atmosphere should also be inert to the action of the radiations and to producing any disagreeable odor in the milk.

'I'he principal object of the present invention is to construct a machine for producing a thin uniform layer ofliquid and maintaining the film for a time sumcient to subject it to radiant energy for a desired length of time.

Another object is to produce such a machine in.

which the time of exposure is controllable whereby an exposure may be obtained sufiicient to produce the desired result and whereby overexposure with detrimental results may be avoided.

Another object is to provide a machine of the class described in which means are provided for supplying a thin film of regulated thickness to a cylinder rotating at a predetermined variable speed and in which means are provided for removing the film from the cylinder.

Another object is to provide a film forming and exposing means particularly adapted for use with a source of radiant energy in the form of a long tube, similar to the mercury vapor `tubes in common use.

Another object is to provide a liquid lm treating device in Which-the energygenerating lamp is cooled to produce the most satisfactory results in a region in which the rays are not eilective in performing a useful function.

A more specific object is to construct and build a machine so designed as to be readily taken apart for cleaning and servicing.

The above objects and others which will be apparent from the detailed description to follow are obtained in a machine such as is illustrated in the drawings in which:

chine with a portion of the driving end of the lm forming cylinder broken away in section to better showits construction.

Figure 2 is a substantially horizontal section of the discharge end of the cylinder showing particularly the closure for that end of the cylinder Y through which der. l p Figure 3 is an end elevation of the machine shown in Figure 1 at the inlet end of the cylinder.

Figure 4 is an end elevation of the machine shown in Figure l at the outlet end of the cylin der.

Figure Sis an enlarged end View of the outlet an inert gas is fed into the cylinend of the-cylinder showing the tube in section and the hlm forming and the liquid collecting means in end elevation.

As illustrated the machine is mounted 0n a supporting structure carried by a base I0. Arched supporting brackets I2 and` I3 are secured by side bars Il to form a rigid frame. An arched bracket I5 secured to the bracket I3 forms a support for a liquid tank I6 which is similar in construction to the milk bowls use'd on cream separators. l

A plate' I'I, somewhat tri-angular in shape is secured to the bracket I2. 'Said plate is provided with a large central opening I8 through which a cylinder I9 extends. Said cylinder is mounted f concentrically in the opening without touching the wall' thereof by three rollers 20 pivotally mounted on bearing pins 2| suitably secured to the plate Il. Said plate and the rollers 20 associated therewith form a rotatable support for the lower end of the cylinder I9.

At its vupper end the cylinder IB is supported for rotation on three rollers 22. The upper roller is mounted on a bearing pin 23 secured to the upper portion of the arched bracket I3. The two lower rollers are supported on bearing pins carried by brackets 24 secured to the upper side portions of the bracket I3. The rollers 22 at the upper end do not contact directly with the cylinder I9 but run in an annular channel 25 formed in a 'flanged pulley 26. Said recess provides means for holding the cylinder against axial movement. The pulley 26 is secured to an outward and radially extending ange 21 rigidly secured to the upper end of the cylinder I9. Said pulley is secured by means of pins 28 threaded into the pulley and extended into openings in the flange. f Cotter pins are utilized for maintaining the flange 21 against the pulley. whereby the cylinder may be readily removed by cotter pins. 1

'I'he pulley 26 is driven by a belt 29 which connects with a pulley 30 on a motor 3|. Any suitable means may be provided for rotating .the cylinder'at the desired rate of speed. For example a variable speed electric motor may be removing the lutilized. It is important to provide a means for controlling the speed of rotation of the cylinder as the speed determines the time of exposure which is an important feature in the treatment with radiant energy. A r,

The cylinder I9 is of a uniform internal diami eter, very finely finished and it is mounted and balanced so as to be driven with a minimum of vibration. For supplying milk tothe cylinder an outlet from the tank I6 controlled by a valve 32 delivers milk through a flexible hose 33 to a delivery condult 34 which terminates within the upper end of the cylinder I9 adjacent the bottom portion thereof. Milk delivered from the tank 'I6-through the conduit 34 flows down the inclined cylinder; I9. The angle of inclination which is fixed by the cylinder mounting is determined by the viscosity of the liquid 'and the rate at whichit is being removed from the cylinder by the film picked up by adhesion with the cylthe direction of rotation being indicated by an arrow in'Figure 5. A vertical upstanding supporting member 31 is rigidly secured to the member 35 spaced from the extension 36. Sairl inember forms a point of attachment for a scraper element 38 which extends substantially parallel to the flange extension 36 and resiliently engages the inner wall of the cylinder. Said scraper element is formed of a material suiiiciently thin and resilient to obtain substantially complete removal of a thin milk film from the Wall of the cylinder. 'I'he flange 36, the member 31 and the scraper element 38 form an inclined trough down which the milk, removed as a film, flows to the lower end where it may be received in any suitable receptacle.

Referring to Figure 5, a film thickness regulating member 39 is secured to the member 35 extending therefrom adjacent the wall of the cylinder I9 at the side which is moving in an upward direction during rotation. Milk adheres to the wall of the cylinder and is carried upwardly. The normalthickness of the milk, assuming the cylinder to be wetted by the milk,

would be determined by the cohesion of the milk particles. The film produced would, however, be too thick for irradiation purposes. It is for this reason that the regulating member 39 is employed. As illustrated, it is of a resilient nature being held in position by adjustable securing bolts 40. Byv adjusting these bolts the thickness of the milk film may be regulated.

At its lower end the member 35 and the structure carried thereby is supported on an end wall 4I, as best shown in Figure 4. Said wall is provided with overhanging lugs which hold the member 35 against lateral movement while permitting endwise movement whereby it may be removed from the cylinder. The wall 4I forms the end Wall of a rectangular tank 42 extending the entire length of the cylinder and of a width substantially greater than the cylinder. The bottom of the tank slopes toward the end opposite the end wall 4I, a drain cock 43 being provided for draining the tank. Said tank is provided largely for the purposes of receiving excess liquid delivered to thev cylinder I9 which is not taken up as a film and which drains from the lower end of the cylinder. The liquid draining to the tank 4I is removed and passed through the machine a second time.

At its upper end the member 35 and the structure associated therewith are carrle'd on a plate 44 which is rigidly secured to the member 35. Said plate is secured by removable lbolts 45 to a member 46 which extends transversely across the arched bracket I3 being rigidly secured to said bracket. The conduit 34 previously referred to for delivering milk to the cylinder extends through an opening in the plate 44 and is brazcd or otherwise secured thereto whereby it is removable with said plate and with the member 35 as a complete assembly.

The source of radiant energy, as illustrated, is a low vapor pressure glow discharge lamp.

Said lamp is provided at each 'end with liquid v mercury electrodes 41 cooled by water jackets 48. Cool water may be introduced at one end through a connection 49 into one jacket and circulatedA therefrom through a cooling jacket 50 extending lthe entire length of thecentral tubular portion 5I of the lamp.

It Will be noted in Figure 5 that the water jacket 50 around the lampextends an angular distance no greater than the distance occupied by the film forming and removing means. Radiatlons from the lamp over this area would be of no value as there is no film to be treated. This is an important feature of lamp construction in connection With a machine of this design. By utilizing either an integral cooling jacket or a jacket closely fitted against the lamp satisfactory cooling may be obtained by utilizing an area which in any event would be ineffective to produce a useful function. The importance of this feature is better 4appreciated when it is understood that ultra-violet radiations which are particularly effective for sterilizing and activating milk will not pass through ordinary tap water to any extent and will not pass through any substance or deposited impurity which might result from thevuse of cooling water. The exact nature of a very effective type of lamp, the precautions necessary to obtain satisfactory results are set forth in detail in the copending application previously referred to.

Water supplied through the inlet 49 after passing through the electrode cooling chambers and the water jacket 50 may be removed through an outlet 52.

'Ihe-lamp tube 5I is supported at its upper end by an inverted U-shaped bracket 53. Said bracket is secured bya clamp around the tube 5I. The lower ends of the bracket are removably secured to the member 46 by the removable bolts 45 previously described. The lower end of the lamp tube 5I is supported by a clamp 54 which is secured to the member 31 previously described.

In order to provide a closure for the lower end of the cylinder I9 a housing 55 is provided; As best shown in Figures l and 2 the housing includes a plate member 56 which fits against the end of the cylinder I9 in a substantially gas tight manner. Said plate at its bottom lside follows the scraper element 38, the upstanding member 31, the member 35 and the film forming member 39 being fltted in asubstantially gas tight manner against these elements except for a cut-away portion 56' which forms an outlet for the milk o whereby the upper portion of the 'cylinder above the member35 may be substantially enclosed. A

large central opening 51 is formed in the member 56 through which the lamp tube .5I extends. An extension housing 58 extending outwardly beyond the end of the cylinder is secured in a gas tight manner to the member 56 and around the tube 5|. Said housing extends as shown in Figure 2 and in Figure 4 vertically and upwardly from oneA Supporting bracket 59,.

I9. Carbon dioxide is particularly suitable as it is heavier than air and maintains an atmosphere in the cylinder suitable fork operation without closing the upper end of the cylinder.

The operation of the machine as described has been explained in connection with the description part by part. A machine of thisv type has been successfully operated with a milk treating capacity of 30 to 40 gallons per hour. 'Ihe film thickness is accurate and can be maintained with the desired limits. The time of exposure is uniform and can be calculated and regulated as desired. 'I'he machine may be readily taken apart due to its construction as described for cleaning and replacing the lamp and for cleaning the cylinder and the film forming and removing means.

The machine has been described as a milk treating device as this machine was developed primarily for that purpose. It is, however, evident that the machine may be used for whatever purpose desired when a thin liquid film is to be treated to a source of radiant energy available in a form such as a tubular lamp. Applicant therefore claims as his invention all modifications and all` the uses falling within the scope of the appended claims. In this description the lamp has only been briefly described. There are at present lamps available for irradiating milk and other uids which could be used in the apparatus desclosed. The apparatus is intended for use with any type of radiant energy producing means which can be used successfully for accomplishing desired results by the treatment of a thin liquid film. All such lamps andv their use applicant contemplates as a part of his invention when utilized in his improved apparatus.

What is claimed is:

1. In a device for irradiating liquids the combination of a supporting structure, a cylinder rotatably mounted in a downwardly inclined position on said structure, means for rotating said cylinder whereby the liquid flows down the bottom of the cylinder and is picked up as a film by the cylinder at the side which is moving upwardly, means for delivering liquid to be treated to the upper end of said cylinder, means within the cylinder extending axially thereof spaced with respect to the -wall for controlling the thickness of the milk film adhering to the wall of the cylinder, said means being positioned near the bottom of the cylinder at the side, moving in an' upward direction, means in the cylinder near the bottom at the side moving downwardly for removing the film therefrom', and means for generating ultra-violet radiations extending axially of the cylinder centrally thereof. I

2.'A device for irradiating liquids comprising a supporting structure, a cylinder rotatably mounted in a downwardly inclined position on said structure, means for rotating said cylinder,

means for delivering liquid to be treated to the upper end of said cylinder, means within the cylinder extending axially thereof spaced with respect to the wall for controlling the thickness of the film adhering to the wall of the cylinder, said meansvbeing positioned near the bottom of the cylinder at the sidemoving in an upward direction, means inthe cylinder near the bottom at the side moving downwardly for removing the film therefrom, means for generating ultra-violetradiations extending axially of the cylinder centrally thereof, and means for maintaining an atmosphere in the cylinder substantially transparent to said radiations. A

3. A device for irradiating liquids comprising a supporting structure, a cylinder rotatably mounted in a downwardly inclined position on said frame structure, means for rotating said cylinder, means for delivering liquid to be treated vto the upper end of said cylinder, means within thickness of the milk film adhering to the wall of I mounted in the cylinder axially thereof and posi-l tioned at the side of the cylinder moving downwardly for removing the film therefrom, a trough positioned to,receive the liquid removed by said element and to deliver it from the cylinder, a container positioned below the lower end of the cylinder for receiving the liquid in excess of that removed as a film, and a means for generating ultra-violet radiations extending axially of the cylinder centrally thereof. l

4. A machine for treating milk comprising a frame structure, a cylinder rotatably mounted in a downwardly inclined position on said frame structure, means foi` rotating said cylinder, means for delivering milk to be treated to the upper end of said cylinder, means within the cylinder extending axially thereof spaced with respect to the a downwardly inclined position on said frame structure, means for rotating said cylinder, means for delivering milk to be treated to the upper end of said cylinder, means within the cylinder extending axially thereof spaced with respect to the -wall for controlling the thickness ofthe milk film adhering to the wall of the cylinder, said means being positioned near the bottom of the cylinder at the side moving in an upward direction,

, means in the cylinder near the bottom at the side moving downwardly for removing the iilm therefrom, means lfor generating ultra-violet radiations extending axially of the cylinder centrally thereof, and means for maintaining an atmosphere in the cylinder substantially transparent to said radiations.

6. A machine for treating milk comprising a framelstructure, a cylinder rotatably mounted in a downwardly inclined position on said frame structure, means for rotating said cylinder, means for delivering milk to be treated to the upper end of said cylinder, means within the cylinder extending axially thereof adjustably spaced with respect to the wall for controlling the thickness of the milk lm adhering to the wall of the cylinder, said means being positioned near the bottom of the cylinder at the side moving in an upward direction, a scraper element mounted in the cylinder axially thereof and positioned at the side of the cylinder moving downwardly for removing the film therefrom, a trough positioned to receive the liquid removed by said element and to deliver it from the cylinder, and means for generating ultra-violet radiations extending axially of the cylinder centrally thereof.

7. A machine for treating milk comprising a frame structure, a cylinder rotatably mounted in a downwardly inclined position on said frame structure, means for rotating said cylinder, means for delivering milk to be treated to the upper end of said cylinder, means within the cylinder extending axially thereof adjustably spaced with respect to the wall for controlling the thickness of the milk film adhering to the wall of the cylinder, said means being positioned near vthe bottom oi! the cylinder at the 4side moving in an upward direction, a scraper element mounted in the cylinder axially thereof and positioned at the side of the cylinder moving downwardly for removing the film therefrom, a trough positioned to receive the liquid removed by said element and to deliver it' from the cylinder, a container positioned below the lower end of the cylinder for receiving the milk in excess of that removed as a film, an enclosure over the lower end of the cylinder, means for supplying an inert atmosphere to the cylinder and means for generating ultraviolet radiations extending axially of the cylinder centrally thereof. 

